The Relation of Accelerometer-Measured Physical Activity and Serum Uric Acid Using the National Health and Nutrition Survey (NHANES) 2003–2004

Objective: Gout is a crystal-induced inflammatory arthritis caused by elevated uric acid. Physical activity has the potential to reduce serum uric acid (SUA), thus improving the disease burden of gout. In this study, we examined the association of objectively-measured physical activity and SUA.Methods: A cross-sectional study was conducted using survey, laboratory, and accelerometer data from the 2003–2004 National Health and Nutrition Examination Survey (NHANES). SUA concentrations (mg/dL) were obtained during an initial exam, and then physical activity (kCal/day) was measured with 7 days of ActiGraph accelerometry in participants (n = 3,475) representative of the ambulatory, non-institutionalized US civilian population. Regression, including restricted cubic splines, was used to assess the relation of physical activity and SUA in bivariate and adjusted models. Covariates included age, gender, race/ethnicity, alcohol use, body mass index, renal function, and urate-lowering therapy.Results: In the bivariate model, physical activity was correlated with SUA concentrations and included a non-linear component (p < 0.01). In the adjusted model, linear splines were employed with a node at the SUA nadir of 5.37mg/dL; this occurred at 703 kCal/day of physical activity. The association of physical activity and SUA was negative from 0 to 703 kCal/day (p = 0.07) and positive >703 kCal/day (p < 0.01 for the change in slope).Conclusion: Physical activity and SUA are associated in a non-linear fashion, with a minimum estimated SUA at 703 kCal/day of objectively-measured physical activity. These findings raise intriguing questions about the use of physical activity as a potential adjunctive therapy in patients with gout, and further interventional studies are needed to elucidate the effects of moderate intensity exercise on SUA concentrations.

Non-modifiable factors as moderators of the relationship between physical activity and brain volume: A cross-sectional UK Biobank study

Background: Grey matter atrophy occurs as a function of ageing and is accelerated in dementia. Previous research suggests physical activity attenuates grey matter loss; however, there appears to be individual variability in this effect. Understanding factors that can affect the relationship between physical activity and brain volume may enable prediction of individual response, and aid in identifying those that gain the greatest neural benefits from physical activity. The current study examined the relationship between objectively-measured physical activity and brain volume; and whether this relationship is moderated by age, sex, or a priori candidate genetic factors. Methods: Data from 10,083 men and women (50 years and over) of the UK Biobank were used to examine: 1) the relationship between objectively-measured physical activity and brain volume; and 2) whether the relationship between objectively-measured physical activity and brain volume is moderated by age, sex, brain-derived neurotrophic factor (BDNF) Val66Met, or apolipoprotein (APOE) e4 allele carriage. All participants underwent a magnetic resonance imaging scan to quantify grey matter volumes, physical activity monitoring via accelerometry, and genotyping. Results: Physical activity was associated with total grey matter volume (B = 0.14, p = 0.001, q = 0.005) and right hippocampal volume (B = 1.45, p = 0.008, q = 0.016). The physical activity*sex interaction predicted cortical grey matter (B = 0.22, p = 0.003, q = 0.004), total grey matter (B = 0.30, p < 0.001, q = 0.001), and right hippocampal volume (B = 3.60, p = 0.001, q = 0.002). Post-hoc analyses revealed males received benefit from higher physical activity levels, in terms of greater cortical grey matter volume (B = 0.13, p = 0.01), total grey matter volume (B=0.23, p < 0.001), and right hippocampal volume (B = 3.05, p = 0.008). No moderating effects of age, APOE e4 allele carriage, or BDNF Val66Met genotype were observed. Discussion: Our results indicate that in males, but not females, an association exists between objectively-measured physical activity and grey matter volume. Future research should evaluate longitudinal brain volumetrics to better understand the nature of sex-effects on the relationship between physical activity and brain volume.

Relationship between Objectively and Subjectively Measured Physical Activity in Adolescents during and after COVID-19 Restrictions

Background: Studying the relationship between subjectively and objectively measured physical activity (PA) can provide viable information on youths’ behaviors. However, the restrictions due to COVID-19 pandemic, which reduced children’s possibilities to be active, may negatively affect it. The aim of this study was to assess the relationship between subjectively and objectively measured PA levels (light, moderate, vigorous, and moderate-to-vigorous) during COVID-19-based restrictions and after they were lifted, and to determine whether such relationships changed in these two periods. Methods: A total of 26 adolescents (58% girls; mean age = 12.4 ± 0.5) wore accelerometers during public restrictions and after they were removed. Participants also completed the International Physical Activity Questionnaire during the same periods. Results: High significant correlations were found at all levels of PA (r = 0.767–0.968) in both time periods, except for moderate PA during restrictions. Comparing the two periods, significantly higher correlations were found for moderate PA (p < 0.001) and moderate-to-vigorous PA (p = 0.003) after restrictions were lifted. Conclusions: In this highly active cohort of adolescents, results emphasize the potential threat of lockdown conditions for youths’ ability to accurately perceive their behaviors, with possible detrimental consequences on the short- and long-term health.

Correlates of Objectively Measured Physical Activity Among People With Multiple Sclerosis: A Cross-Sectional Study

Background: Identifying correlates of physical activity (PA) for people with multiple sclerosis (MS) is essential to design effective PA interventions.Methods: Participants completed a battery of questionnaires and wore an ActiGraph accelerometer. Light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) (min/day) were calculated. Associations were examined using multiple linear regression adjusted for demographic and clinical confounders.Results: Fifty-eight adults with MS participated (mean ± SD age: 56.8 ± 9.2 yr; 67% women). MS type was associated with time in LPA. Participants with secondary progressive MS (B = −54.0, 95% CI −84.7 to −23.3) and primary progressive MS (B = −42.9, 95% CI −77.5 to −8.3) spent less time in LPA than those with relapsing remitting MS. Walking capacity, assessed using the 12-item MS walking scale (MSWS-12), was associated with time in MVPA (B = −0.36, 95% CI −0.72 to −0.01).Conclusion: This work identifies walking capacity and type of MS as correlates of PA, which may indicate development of interventions to promote PA.

Associations Between Physical Fitness, Objectively Measured Physical Activity and Academic Performance

There is evidence that physical activity (PA) can improve the academic performance. We recruited healthy adolescent girls, aged 11–12 years, and measured their PA with the accelerometer ActiGraph GT3X for the consecutive 5 days. Physical fitness (PF) was measured with eight motoric tests and three anthropometry measures. Academic performance (AP) was assessed for the six academic narrated school subjects. The results revealed that the girls were more physically active during the week days and less active at weekend (557 vs. 516 counts/min). Physical education grade shows the highest overall correlations with the results of the PF test battery (r = 0.53–0.95, p &lt; 0.01). Nevertheless, correlations surprisingly decrease for the combined daily PA (r = 0.45), especially the weekend PA (r = 0.28). Grade point average and PF correlated moderately (r = 0.43-0.64), while they were moderate to high for PA (r = 0.59–0.87). Many questions arose after the completion of the present study and several new topics opened up, such as the question of how parental education affects the duration of PA and AP of the children and the influence of the place of residence AP of the children.

Accelerometry Correlates in Body Composition, Physical Fitness, and Disease Symptom Burden: A Pilot Study in End-Stage Renal Disease

There is strong evidence that hemodialysis (HD) patients with a sedentary lifestyle have a higher risk of death compared to peers who engage in regular physical activity. Therefore, monitoring physical activity is of utmost importance. However, there is a lack of data on objectively measured physical activity behaviors in HD patients. Therefore, this study aimed to objectively measure physical activity in HD patients throughout the week, with particular attention to dialysis and non-dialysis days. We also examined how objectively measured physical activity correlated with physical fitness, body composition, and disease burden. Daily physical activity, body composition, serum parameters, comorbidity index, sit-to-stand, and hand-grip strength tests were measured in 14 HD patients. Daily physical activity was measured using the Actigraph GT9X accelerometer. The Dialysis Symptom Index questionnaire was also used. We found significant differences in anthropometric variables (weight, body mass index, overhydration, lean tissue index, and fat tissue index, all p &lt; 0.05) and phase angle (p &lt; 0.01) between HD patients reaching and patients not reaching physical activity guidelines for patients with chronic diseases. HD patients showed to be less active during dialysis days compared to non-dialysis days as indicated in sedentary time (–11.7%; p = 0.001), light (–47.3%; p = 0.003), moderate (–51.5%; p = 0.001), moderate to vigorous (–49.3%; p = 0.001), and vigorous (–34.3%; p = 0.067) physical activity. No significant correlations were found among serum parameters, symptom burden, and comorbidity burden, but a very large and positive correlation was found between phase angle and total moderate to vigorous physical activity (p &lt; 0.01). Our findings support the need to implement physical activity on dialysis days in HD units to mitigate the effects of sedentary behavior. Prospective, long-term studies evaluating the use of accelerometers in HD patients and their effects on physical activity are needed.

Objectively-measured physical activity and stress levels in workers: a systematic review physical activity and stress in workers

To investigate the relationship between objectively measured physical activity and occupational stress in different work environments. This systematic review, registered in the PROSPERO database (CRD42020214884), followed the PRISMA methodology. The search took place in October/2020 in the following databases: Web of Science, SPORTDiscus, MedLine/PubMed, PsycINFO, EMBASE, OVID MEDLINE, Scielo and CINAHL. Keywords related to eligible participants (adults and workers), interventions (physical activity objectively measured), comparison (control group or baseline), outcome (stress), and study design (observational studies) were combined using Boolean terms. From 1,524 identified records, 12 articles were included, totaling 2,082 workers. 66.7% of the studies were carried out in Europe and 50.0% among health professionals. Blue collar workers (20.7% [n = 430]) and white collar workers (18.3% [n = 382]), medical resident (6.5% [n = 135]) and protection services (9.7% [n = 202]) were the predominant occupations. Physical activity was higher in blue-collar workers than in white-collar workers, and shift-working nurses were more active compared to non-shift workers and office workers. Increased mental workload was not associated with time spent on physical activities in most studies (10 [83.3%)]). Some studies showed that light physical activity was associated with higher levels of stress and moderate to vigorous physical activity was beneficial for reducing stress dimensions. In conclusion, most studies did not find an association between objectively measured physical activity and the level of stress in workers. Studies with robust methodologies and covering different groups of workers remain necessary.